Electronic apparatus

ABSTRACT

According to one embodiment, an electronic apparatus is provided with a circuit board contained in a case and including a first surface and a second surface formed on the reverse side of the first surface, a first heat generating component mounted on the first surface, a second heat generating component mounted on the second surface, a radiator section located off the circuit board, a first heat transfer member extending along the first surface and provided between the first heat generating component and the radiator section, and a second heat transfer member extending along the second surface and provided between the second heat generating component and the radiator section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2006-140315, filed May 19, 2006, theentire contents of which are incorporated herein by reference.

BACKGROUND

1. Field

One embodiment of the invention relates to an electronic apparatus onwhich heat generating components are mounted, and to, for example, heatradiating structure of the heat generating components.

2. Description of the Related Art

An electronic apparatus, such as a portable computer, is mounted withheat generating components including a CPU. A remote heat exchanger(RHE) is an example of a structure for cooling these heat generatingcomponents. The RHE is basically composed of heat pipes, radiator fins,and a cooling fan. The radiator fins are located off a circuit boardand, for example, near a peripheral wall of a case. The cooling fancools the radiator fins. The heat pipes are provided between the heatgenerating components and the radiator fins and transfer heat from theheat generating components to the radiator fins.

An electronic apparatus having a cooling unit for cooling a plurality ofheat generating components is disclosed in Jpn. Pat. Appln. KOKAIPublication No. 10-107469, for example. This electronic apparatusincludes, for example, three heat generating components, three heatpipes, and a fin unit. The heat pipes are arranged between the fin unitand the heat generating components.

The power consumption of electronic components mounted in electronicapparatuses has become higher and higher in recent years. It is believedthat any other heat generating components than CPUs, such as graphicchips, memories, etc., should preferably be directly cooled by means ofan RHE in the future. In this case, one end of a heat transfer member,such as a heat pipe, may possibly be attached to each heat generatingcomponent, and the other end of the heat pipe to radiator members, suchas radiator fins.

In attaching heat pipes to a plurality of heat generating componentsarranged side by side horizontally, for example, the heat pipes are alsoarranged adjacent to one another horizontally. In order to keep anecessary space for the lead-around of the adjacent heat pipes toradiator members, gaps of a predetermined or larger width must beprovided between the heat generating components.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A general architecture that implements the various feature of theinvention will now be described with reference to the drawings. Thedrawings and the associated descriptions are provided to illustrateembodiments of the invention and not to limit the scope of theinvention.

FIG. 1 is an exemplary perspective view of a portable computer accordingto a first embodiment of the invention;

FIG. 2 is an exemplary perspective view showing the interior of a caseof the portable computer according to the first embodiment;

FIG. 3 is an exemplary sectional view of a circuit board taken alongline F3-F3 of FIG. 2;

FIG. 4 is an exemplary sectional view of the portable computer takenalong line F4-F4 of FIG. 2;

FIG. 5 is an exemplary sectional view of the portable computer takenalong line F5-F5 of FIG. 2;

FIG. 6 is an exemplary exploded sectional view of the portable computershown in FIG. 5;

FIG. 7 is an exemplary perspective view showing the interior of a caseof a portable computer according to a second embodiment of theinvention;

FIG. 8 is an exemplary perspective view showing the interior of a caseof a portable computer according to a third embodiment of the invention;

FIG. 9 is an exemplary sectional view of the portable computer takenalong line F9-F9 of FIG. 8;

FIG. 10 is an exemplary perspective view showing the interior of a caseof a portable computer according to a fourth embodiment of theinvention; and

FIG. 11 is an exemplary sectional view of the portable computer takenalong line F11-F11 of FIG. 10.

DETAILED DESCRIPTION

Various embodiments according to the invention will be describedhereinafter with reference to the accompanying drawings. In general,according to one embodiment of the invention, An electronic apparatus isprovided with a case; a circuit board contained in the case andincluding a first surface and a second surface formed on the reverseside of the first surface; a first heat generating component mounted onthe first surface of the circuit board; a second heat generatingcomponent mounted on the second surface of the circuit board; a radiatorsection located off the circuit board; a first heat transfer memberextending along the first surface of the circuit board and providedbetween the first heat generating component and the radiator section;and a second heat transfer member extending along the second surface ofthe circuit board and provided between the second heat generatingcomponent and the radiator section.

Embodiments of the present invention applied to portable computers willnow be described with reference to the accompanying drawings.

FIGS. 1 to 6 show a portable computer 1 as an electronic apparatusaccording to a first embodiment of the invention. As shown in FIG. 1,the portable computer 1 includes a body 2 and a display unit 3.

The body 2 includes a body base 4 and a body cover 5. The cover 5 iscombined with the base 4 from above. The body 2 is provided with abox-shaped case 6 formed of the base 4 and the cover 5 that are joinedtogether. The case 6 has a top wall 6 a, a peripheral wall 6 b, and abottom wall 6 c. The top wall 6 a supports a keyboard 7. The peripheralwall 6 b has a front peripheral wall 6ba, a rear peripheral wall 6 bb, aleft-hand peripheral wall 6 bc, and a right-hand peripheral wall 6 bd.

The display unit 3 includes a display hosing 8 and a liquid crystalpanel 9 contained in the hosing 8. The display panel 9 has a displayscreen 9 a. The screen 9 a is exposed to the outside of the displayhousing 8 through an opening 8 a in the front face of the housing 8.

The display unit 3 is supported on the rear end portion of the case 6 bya hinge device. Thus, the display unit 3 is swingable between a closedposition in which it is brought down to cover the top wall 6 a fromabove and an open position in which it rises to allow the top wall 6 ato be exposed.

As shown in FIG. 2, the case 6 contains a circuit board 11, a coolingfan 12, first and second heat pipes 13 and 14, and a radiator section10. The radiator section 10 is located off the circuit board 11. Theradiator section 10 has first and second radiator members 15 and 16.

The circuit board 11 has a first surface 11 a and a second surface 11 b.An example of the first surface 11 a is the upper surface of the circuitboard 11. The first surface 11 a is the so-called obverse that faces thetop wall 6 a. An example of the second surface 11 b is the lower surfaceof the circuit board 11, which is formed on the reverse side of thefirst surface 11 a. The second surface 11 b is the so-called reversethat faces the bottom wall 6 c.

A first heat generating component 21, for example, is mounted on thefirst surface 11 a of the circuit board 11. A second heat generatingcomponent 22, for example, is mounted on the second surface 11 b of thecircuit board 11. A plurality of other circuit components (not shown) ismounted on the circuit board 11. The heat generating components 21 and22, among other circuit components mounted on the circuit board 11, arecomponents that generate a particularly large quantity of heat, forexample.

Examples of the heat generating components 21 and 22 include CPUs,graphics chips, various chip sets, memories, etc. However, heatgenerating components to which the embodiment of the invention isapplicable are not limited to these examples. The heat generatingcomponents 21 and 22 may be any of various electronic components thatrequire heat radiation. The first and second heat generating components21 and 22, compared with the cooling fan 12, are located on the side ofthe front peripheral wall 6 ba, that is, closer to the peripheral wallon the user side, for example.

As shown in FIGS. 2 and 3, one end portion 13 a of the first heat pipe13 is attached to the first heat generating component 21. The first heatpipe 13 is an example of a first heat transfer member. One end portion14 a of the second heat pipe 14 is attached to the second heatgenerating component 22. The second heat pipe 14 is an example of asecond heat transfer member. Each of the first and second heat pipes 13and 14 is thermally connected to the first or second heat generatingcomponent 21 or 22 through a heat receiving block 24. More specifically,a groove 24 a, for example, is cut in each heat receiving block 24 so asto extend along the direction of extension of the first or second heatpipe 13 or 14. The heat receiving block 24 is formed of, for example, ametal that has high thermal conductivity.

The respective one end portions 13 a and 14 a of the first and secondheat pipes 13 and 14 are fitted individually in, for example, therespective grooves 24 a of the heat receiving blocks 24. Specifically,the first and second heat pipes 13 and 14 are staked in the grooves 24a. Each heat receiving block 24 is placed on the first or second heatgenerating component 21 or 22 with a heat transfer member 25 betweenitself and the component 21 or 22. An example of the heat transfermember 25 is grease, a heat transfer sheet, or the like.

As shown in FIG. 2, each heat receiving block 24 is fixed to the circuitboard 11 with a fixture 26. The fixture 26 has a cover portion 26 a thatsupports the heat receiving block 24 and leg portions 26 b that extendfrom the cover portion 26 a toward the circuit board 11 and are screwedto the circuit board 11. The heat receiving blocks 24 and the heat pipes13 and 14 are sandwiched between the circuit board 11 and the fixtures26, whereby their respective positions are fixed. The method of mountingthe heat pipes 13 and 14 is not limited to fitting but may be any othermethod, such as soldering.

As shown in FIG. 2, the cooling fan 12 is located near the left-handperipheral wall 6 bc in the case 6. That part of the circuit board 11which corresponds to the cooling fan 12 is cut out so as not tointerfere with the fan 12. Specifically, as shown in FIG. 4, the coolingfan 12 is disposed in a position off the circuit board 11. The fan 12 islocated side by side with the circuit board 11 along a direction (e.g.,the horizontal in the present embodiment) parallel to the surfaces 11 aand 11 b of the board 11.

For example, a plurality of exhaust vents 28 is formed in the left-handperipheral wall 6 bc of the case 6 opposed to the cooling fan 12. Theexhaust vents 28 open to the outside of the case 6. The cooling fan 12has intake ports 12 a through which air is drawn in and an exhaust port12 b through which drawn air is discharged. The intake ports 12 a openin, for example, the upper and lower surfaces of the cooling fan 12,individually. The exhaust port 12 b opens in a side face of the fan 12and faces the exhaust vents 28 of the left-hand peripheral wall 6 bc.The cooling fan 12 discharges air toward the exhaust vents 28.

The first and second radiator members 15 and 16 are located near theleft-hand peripheral wall 6 bc of the case 6 that is situated off thecircuit board 11. More specifically, as shown in FIG. 2, both the firstand second radiator members 15 and 16 are disposed between the exhaustport 12 b of the cooling fan 12 and the exhaust vents 28 of theleft-hand peripheral wall 6 bc. The second radiator member 16 is locatedside by side with the first radiator member 15. Both the first andsecond radiator members 15 and 16 are opposed to the cooling fan 12.They extend parallel to each other along a direction across thedirection of air discharge by the cooling fan 12. The radiator members15 and 16 are arranged back and forth along flows of air. In the presentembodiment, the first radiator member 15 is located, for example,between the second radiator member 16 and the cooling fan 12.

An example of each of the first and second radiator members 15 and 16 isformed by assembling a plurality of fin elements 31. Each fin element 31is a plate-like member having, for example, a rectangular shape. Eachfin element 31 is formed of a metal with high thermal conductivity, suchas aluminum. The fin elements 31 are spaced apart from one another andhave their respective planar surfaces extending along flows of air fromthe cooling fan 12.

The first heat pipe 13 extends along the first surface 11 a of thecircuit board 11 from the one end portion 13 a attached to the firstheat generating component 21 toward the left-hand peripheral wall 6 bcof the case 6. As mentioned before, the first heat generating component21 is situated nearer to the front peripheral wall 6 ba of the case 6than the cooling fan 12 is. The cooling fan 12 has a front side face 12c opposite the front peripheral wall 6 ba of the case 6. The first heatpipe 13 extends along the front side face 12 c of the fan 12.

The first heat pipe 13 that extends beyond the circuit board 11 is benttoward the first radiator member 15. As shown in FIGS. 5 and 6, thefirst heat pipe 13 bent in this manner is bent toward the center of thefirst radiator member 15 with respect to the vertical. Thus, the firstheat pipe 13 is bent toward the bottom wall 6 c of the case 6.

The distal end portion of the first heat pipe 13 extends along theexhaust port 12 b of the cooling fan 12 and penetrates the fin elements31. In other words, the first radiator member 15 is formed of the finelements 31 that have a center hole each and are penetrated by the firstheat pipe 13.

Specifically, the first heat pipe 13 is provided between the first heatgenerating component 21 and the first radiator member 15. The one endportion 13 a of the first heat pipe 13 is thermally connected to thefirst heat generating component 21. The other end portion 13 b of thefirst heat pipe 13 is thermally connected to the first radiator member15. The first heat pipe 13 has a coolant fluid therein, which transfersheat between the opposite end portions 13 a and 13 b taking advantage ofheat of vaporization and capillarity. The first heat pipe 13 transfersheat generated by the first heat generating component 21 to the firstradiator member 15.

The second heat pipe 14 extends along the second surface 11 b of thecircuit board 11 from the one end portion 14 a attached to the secondheat generating component 22 toward the left-hand peripheral wall 6 bcof the case 6. As mentioned before, the second heat generating component22 is situated nearer to the front peripheral wall 6 ba of the case 6than the cooling fan 12 is. The second heat pipe 14 extends along thefront side face 12 c of the fan 12.

The second heat pipe 14 that extends beyond the circuit board 11 is benttoward the second radiator member 16. As shown in FIGS. 5 and 6, thesecond heat pipe 14 bent in this manner is bent toward the center of thesecond radiator member 16 with respect to the vertical. Thus, the secondheat pipe 14 is bent toward the top wall 6 a of the case 6. The distalend portion of the second heat pipe 14 extends along the exhaust port 12b of the cooling fan 12 and penetrates the fin elements 31. The secondradiator member 16 is formed of the fin elements 31 that are penetratedby the second heat pipe 14.

The second heat pipe 14 is provided between the second heat generatingcomponent 22 and the second radiator member 16. The one end portion 14 aof the second heat pipe 14 is thermally connected to the second heatgenerating component 22. The other end portion 14 b of the second heatpipe 14 is thermally connected to the second radiator member 16. Thesecond heat pipe 14 transfers heat generated by the second heatgenerating component 22 to the second radiator member 16.

In order to increase the area of installation on the heat receivingblocks 24, for example, the first and second heat pipes 13 and 14,having a diameter of, e.g., 6 mm, are flattened to a vertical thicknessof about 3 mm when they are worked.

The first and second heat pipes 13 and 14 extend along the same sideface 12 c of the cooling fan 12. When viewed from above the case 6, forexample, the heat pipes 13 and 14 extend substantially along the sametrack.

The following is a description of the operation of the portable computer1.

When the portable computer 1 is worked, the first and second heatgenerating components 21 and 22 generate heat. Part of the heatgenerated by the first heat generating component 21 is transferred tothe first radiator member 15 by the first heat pipe 13. Part of the heatgenerated by the second heat generating component 22 is transferred tothe second radiator member 16 by the second heat pipe 14.

When the cooling fan 12 is actuated, air is discharged through theexhaust port 12 b, whereupon the first and second radiator members 15and 16 are cooled. The heat transferred from the heat generatingcomponents 21 and 22 to the first and second radiator members 15 and 16is transferred to air discharged from the cooling fan 12, and the heatedair is discharged to the outside of the case 6 through the exhaust vents28. Thus, cooling of the first and second heat generating components 21and 22 is accelerated.

According to the portable computer 1 constructed in this manner, theplurality of heat generating components 21 and 22 can be cooled andmounted with high density. Specifically, the heat pipes 13 and 14 areattached, respectively, to the heat generating components 21 and 22 thatare mounted separately on the obverse and reverse of the circuit board11, and the radiator members 15 and 16 to which the heat pipes 13 and 14are connected are gathered in one place and cooled by, for example, theone cooling fan 12. Thus, cooling of the plurality of heat generatingcomponents 21 and 22 can be accelerated.

By mounting the plurality of heat generating components 21 and 22separately on the obverse and reverse of the circuit board 11, the firstand second heat pipes 13 and 14 can be prevented from adjoining eachother along one surface of the circuit board 11. Specifically, thenecessity of providing a space for the lead-around of the heat pipes canbe reduced, so that the first and second heat generating components 21and 22 can be located close to each other on the obverse and reversesides. Thus, the heat generating components 21 and 22 can be mountedwith high density.

If the heat generating components 21 and 22 can be located close to eachother, it is possible to reduce regions in the circuit board 11 wheretemperature increases, so that a layout configuration with high coolingefficiency can be achieved. For example, the first and second heatgenerating components 21 and 22 can be intensively mounted in a regionunder the keyboard 7 that is not accessible to a user, avoiding a spaceunder a palm rest or the like that can be touched by the user.

If the first and second heat pipes 13 and 14 are prevented fromadjoining each other along the one surface of the circuit board 11, thedegree of freedom of the lead-around of the heat pipes increases. Thishelps the lead-around of the heat pipes 13 and 14 in the case 6 that islimited in space. For example, the first and second heat pipes 13 and 14both extend along the same side face 12 c of the cooling fan 12. Sincethe two heat pipes 13 and 14 go around the cooling fan 12 from the samedirection, they can be led around more easily in the case 6 with thelimited space. In other words, this leads to miniaturization of theportable computer 1.

In order to tilt the keyboard 7 so that its back is raised (i.e., itbecomes higher with distance from the user) when in use, for example,some users operate the portable computer 1 with its back raised. If theportable computer 1 according to the present embodiment is tilted sothat its back is raised, the first and second radiator members 15 and 16are situated higher than the first and second heat generating components21 and 22 with respect to the vertical. Thus, the first and second heatpipes 13 and 14 are in a bottom-heat mode such that their respectiveheat receiving portions 13 a and 14 a are situated lower than their heatradiating portions 13 b and 14 b. Based on the principle of itsoperation that utilizes capillarity, a heat pipe displays higher heattransfer efficiency in a bottom-heat mode than in the top-heat mode.

Since the two heat pipes 13 and 14 can be led around the cooling fan 12from the same direction, according to the portable computer 1 of thepresent embodiment, a layout design can be made such that both the heatpipes 13 and 14 are easily brought to the bottom-heat mode.

If the first and second radiator members 15 and 16 are arranged back andforth along the flows of air from the cooling fan, the two radiatormembers 15 and 16 can be effectively cooled by means of, e.g., the onecooling fan 12.

The overall mounting height of modules that are arranged in the case 6can be reduced by arranging the cooling fan 12 side by side with thecircuit board 11 along a direction parallel to the surfaces of thecircuit board. Thus, the case 6 can be made thinner than in the casewhere the cooling fan 12 is placed on the circuit board 11.

A portable computer 41 as an electronic apparatus according to a secondembodiment of the invention will now be described with reference to FIG.7. Like numbers are used to designate those parts which have the samefunctions as their counterparts in the portable computer 1 according tothe first embodiment, and a description thereof is omitted.

A case 6 of the portable computer 41 contains third and fourth heatpipes 42 and 43 and an additional radiator section 40, as well as acircuit board 11, a cooling fan 12, first and second heat pipes 13 and14, and a radiator section 10. The radiator section 40 has third andfourth radiator members 44 and 45.

A third heat generating component 46, for example, is mounted on a firstsurface 11 a of the circuit board 11. A fourth heat generating component47, for example, is mounted on a second surface. 11 b of the circuitboard 11. Like first and second heat generating components 21 and 22,the third and fourth heat generating components 46 and 47, among othercircuit components mounted on the circuit board 11, generate a largerquantity of heat, for example.

As shown in FIG. 7, one end portion 42 a of the third heat pipe 42 isattached to the third heat generating component 46. The third heat pipe42 is an example of a third heat transfer member. One end portion 43 aof the fourth heat pipe 43 is attached to the fourth heat generatingcomponent 47. The fourth heat pipe 43 is an example of a fourth heattransfer member. Each of the third and fourth heat pipes 42 and 43, likeeach of the first and second heat pipes 13 and 14, is thermallyconnected to the third and fourth heat generating component 46 or 47through a heat receiving block 24.

The cooling fan 12 is located side by side with the circuit board 11along a direction parallel to the surfaces 11 a and 11 b of the board11. For example, a plurality of exhaust vents 48 is formed in a rearperipheral wall 6 bb of the case 6 opposed to the cooling fan 12. Theexhaust vents 48 open to the outside of the case 6. The cooling fan 12has an additional exhaust port 12 d through which air is discharged in adirection different from that of air discharged through an exhaust port12 b. The exhaust port 12 d of the fan 12 faces the exhaust vents 48 ofthe rear peripheral wall 6 bb. The cooling fan 12 discharges air towardthe exhaust vents 48 through the exhaust port 12 d.

The third and fourth radiator members 44 and 45 are located near therear peripheral wall 6 bb of the case 6 that is located off the circuitboard 11. Both the radiator members 44 and 45 are disposed between theexhaust port 12 d of the cooling fan 12 and the exhaust vents 48 of therear peripheral wall 6 bb. The fourth radiator member 45 is located sideby side with the third radiator member 44. Both the third and fourthradiator members 44 and 45 are opposed to the cooling fan 12. Theradiator members 44 and 45 extend parallel to each other and arearranged back and forth along flows of air.

The third heat pipe 42 extends along the first surface 11 a of thecircuit board 11 from the one end portion 42 a attached to the thirdheat generating component 46 toward the rear peripheral wall 6 bb of thecase 6.

The third heat pipe 42 that extends beyond the circuit board 11 is benttoward the third radiator member 44. As shown in FIG. 7, the third heatpipe 42 bent in this manner is bent toward the bottom wall 6 c of thecase 6 so as to correspond to the center of the third radiator member 44with respect to the vertical. The distal end portion of the third heatpipe 42 extends along the exhaust port 12 d of the cooling fan 12 andpenetrates a plurality of fin elements 31.

Specifically, the third heat pipe 42 is provided between the third heatgenerating component 46 and the third radiator member 44. The one endportion 42 a of the third heat pipe 42 is thermally connected to thethird heat generating component 46. The other end portion 42 b of thethird heat pipe 42 is thermally connected to the third radiator member44. The third heat pipe 42 transfers heat generated by the third heatgenerating component 46 to the third radiator member 44.

The fourth heat pipe 43 extends along the second surface 11 b of thecircuit board 11 from the one end portion 43 a attached to the fourthheat generating component 47 toward the rear peripheral wall 6 bb of thecase 6. The fourth heat pipe 43 that extends beyond the circuit board 11is bent toward the fourth radiator member 45. The fourth heat pipe 43bent in this manner is bent toward the top wall 6 a of the case 6 so asto correspond to the center of the fourth radiator member 45with-respect to the vertical. The distal end portion of the fourth heatpipe 43 extends along the exhaust port 12 d of the cooling fan 12 andpenetrates a plurality of fin elements 31.

The fourth heat pipe 43 is provided between the fourth heat generatingcomponent 47 and the fourth radiator member 45. The one end portion 43 aof the fourth heat pipe 43 is thermally connected to the fourth heatgenerating component 47. The other end portion 43 b of the fourth heatpipe 43 is thermally connected to the fourth radiator member 45. Thefourth heat pipe 43 transfers heat generated by the fourth heatgenerating component 47 to the fourth radiator member 45.

According to the portable computer 41 constructed in this manner, as inthe portable computer 1 according to the first embodiment, the pluralityof heat generating components 21, 22, 46 and 47 can be cooled andmounted with high density. According to this portable computer 41, whencompared with a case where heat pipes are arranged extending along onlyone side of a circuit board, for example, a lot of heat generatingcomponents can be cooled by means of the one cooling fan 12.

Since the heat generating components 21, 22, 46 and 47 are mountedseparately on the obverse and reverse of the circuit board 11, thedegree of freedom of the lead-around of the heat pipes 13, 14, 42 and 43increases. For example, the four heat generating components 21, 22, 46and 47 can be mounted with high density, and the radiator members 15,16, 44 and 45 that are connected to the heat pipe 13, 14, 42 and 43 canbe gathered in one place as they are cooled.

A portable computer 51 as an electronic apparatus according to a thirdembodiment of the invention will now be described with reference toFIGS. 8 and 9. Like numbers are used to designate those parts which havethe same functions as their counterparts in the portable computers 1 and41 according to the first and second embodiments, and a descriptionthereof is omitted.

A case 6 of the portable computer 51 contains third and fourth heatpipes 42 and 43 and third and fourth radiator members 44 and 45, as wellas a circuit board 11, a cooling fan 12, first and second heat pipes 13and 14, and first and second radiator members 15 and 16.

As shown in FIGS. 8 and 9, each of the first and third radiator members15 and 44 has a plurality of fin elements 31 and a top cover portion 52that extends covering the respective upper ends of all the fin elements31. The top cover portion 52 forms an example of an upper part of eachof the first and third radiator members 15 and 44. The cover portion 52may be formed either integrally with or independently of the finelements 31. It is thermally connected to the fin elements 31.

On the other hand, each of the second and fourth radiator members 16 and45 has a plurality of fin elements 31 and a bottom cover portion 53 thatextends covering the respective lower ends of all the fin elements 31.The bottom cover portion 53 forms an example of a lower part of each ofthe second and fourth radiator members 16 and 45. The cover portion 53may be formed either integrally with or independently of the finelements 31. It is thermally connected to the fin elements 31.

As shown in FIG. 9, the first and third heat pipes 13 and 42 that arebent toward the first and third radiator members 15 and 44,respectively, are attached to the respective top cover portions 52 ofthe first and third radiator members 15 and 44, respectively. Thus, thefirst and third heat pipes 13 and 42 are attached to the upper surfacesof the first and third radiator members 15 and 44, respectively.

The second and fourth heat pipes 14 and 43 that are bent toward thesecond and fourth radiator members 16 and 45, respectively, are attachedto the respective bottom cover portions 53 of the second and fourthradiator members 16 and 45, respectively. Thus, the second and fourthheat pipes 14 and 43 are attached to the lower surfaces of the secondand fourth radiator members 16 and 45, respectively.

According to the portable computer 51 constructed in this manner, as inthe portable computer 1 according to the first embodiment, the pluralityof heat generating components 21, 22, 46,and 47 can be cooled andmounted with high density.

If the first and third heat pipes 13 and 42 that extend along the firstsurface 11 a of the circuit board 11 are attached to the respectiveupper surfaces of the first and third radiator members 15 and 44,moreover, they need hardly be bent vertically relative to the case 6.Likewise, if the second and fourth heat pipes 14 and 43 that extendalong the second surface 11 b of the circuit board 11 are attached tothe respective lower surfaces of the second and fourth radiator members16 and 45, they need hardly be bent vertically relative to the case 6.These circumstances lead to improvement of the manufacturability of theportable computer 51 and reduction in cost thereof.

If the first and third heat pipes 13 and 42, for example, need not besubstantially deformed vertically relative to the case 6, moreover, theend portions 13 b and 42 b attached to the first and third radiatormembers 15 and 44, respectively, can be restrained from being situatedlower than the end portions 13 a and 42 a attached to the first andthird heat generating components 21 and 46, respectively. Thus, thetop-heat mode to which the first and third heat pipes 13 and 42 arebrought can be eased. This leads to improvement of the coolingefficiency of the portable computer 51.

A portable computer 61 as an electronic apparatus according to a fourthembodiment of the invention will now be described with reference toFIGS. 10 and 11. Like numbers are used to designate those parts whichhave the same functions as their counterparts in the portable computers1 and 51 according to the first and third embodiments, and a descriptionthereof is omitted.

A case 6 of the portable computer 61 contains a circuit board 11, acooling fan 12, first and second heat pipes 13 and 14, and a radiatorsection 63. The radiator section 63 has one radiator member 62. Theradiator member 62 has a plurality of fin elements 31, a top coverportion 52, and a bottom cover portion 53.

The top and bottom cover portions 52 and 53 are attached to the upperand lower ends, respectively, of the fin elements 31 so as to coverthem. The radiator member 62 is located between an exhaust port 12 b ofthe cooling fan 12 and exhaust vents 28 of a left-hand peripheral wall 6bc. The radiator member 62 is opposed to the cooling fan 12.

As shown in FIGS. 10 and 11, the first heat pipe 13 that is bent towardthe radiator member 62 is attached to the top cover portion 52 of theradiator member 62. Specifically, the first heat pipe 13 is attached toan upper part of the radiator member 62.

The second heat pipe 14 that is bent toward the radiator member 62 isattached to the bottom cover portion 53 of the radiator member 62.Specifically, the second heat pipe 14 is attached to a lower part of theradiator member 62.

According to the portable computer 61 constructed in this manner, aplurality of heat generating components 21 and 22 can be cooled andmounted with high density. Specifically, the first and second heat pipes13 and 14 are attached, respectively, to the heat generating components21 and 22 that are mounted separately on the obverse and reverse of thecircuit board 11, and they are connected to the one radiator member 62.Thus, cooling of the plurality of heat generating components 21 and 22can be accelerated by the one radiator member 62.

If the radiator member 62 is cooled by the cooling fan 12, for example,the cooling effect of the first and second heat generating components 21and 22 is further enhanced. For the same reason as that for the portablecomputer 1 according to the first embodiment, the first and second heatpipes 13 and 14 can be brought to the bottom-heat mode when the portablecomputer 61 in operation is tilted with its back raised.

If the first and second heat pipes 13 and 14 are attached to the upperand lower surfaces, respectively, of the radiator member 62, themanufacturability of the portable computer 61 can be improved withreduced cost for the same reason as that for the portable computer 51according to the third embodiment. The first heat pipe 13 can ease thetop-heat mode.

Although the portable computers 1, 41, 51 and 61 according to the firstto fourth embodiments have been described herein, the present inventionis not limited to these embodiments. The components according to thefirst to fourth embodiments may be combined as required.

For example, the first and second heat pipes 13 and 14 according to thethird embodiment may be attached to the one radiator member 62 accordingto the fourth embodiment, and the third and fourth heat pipes 42 and 43to another radiator member 62. An example of each of the first to fourthheat transfer members may be any other member with a high heat transfercoefficient.

Electronic apparatuses to which the present invention is applicable arenot limited to portable computers. The invention is applicable tovarious other electronic apparatuses, such as digital cameras, videocameras, personal digital assistants, etc.

While certain embodiments of the inventions have been described, theseembodiments have been presented by way of example only, and are notintended to limit the scope of the inventions. Indeed, the novel methodsand systems described herein may be embodied in a variety of otherforms; furthermore, various omissions, substitutions and changes in theform of the methods and systems described herein may be made withoutdeparting from the spirit of the inventions. The accompanying claims andtheir equivalents are intended to cover such forms or modifications aswould fall within the scope and spirit of the inventions.

1. An electronic apparatus comprising: a case; a circuit board containedin the case and including a first surface and a second surface formed onthe reverse side of the first surface; a first heat generating componentmounted on the first surface of the circuit board; a second heatgenerating component mounted on the second surface of the circuit board;a radiator section located off the circuit board; a first heat transfermember extending along the first surface of the circuit board andprovided between the first heat generating component and the radiatorsection; and a second heat transfer member extending along the secondsurface of the circuit board and provided between the second heatgenerating component and the radiator section.
 2. An electronicapparatus according to claim 1, which further comprises a cooling fancontained in the case, and wherein the radiator section includes a firstradiator member located opposite the cooling fan and a second radiatormember located side by side with the first radiator member and opposedto the cooling fan, the first heat transfer member is thermallyconnected to the first heat generating component and the first radiatormember, and the second heat transfer member is thermally connected tothe second heat generating component and the second radiator member. 3.An electronic apparatus according to claim 2, wherein the case includesa wall in which an exhaust vent opens, the cooling fan includes anexhaust port through which air is discharged toward the exhaust vent,and the first radiator member and the second radiator member are bothlocated between the exhaust port of the cooling fan and the exhaust ventof the wall and arranged back and forth along a flow of the air.
 4. Anelectronic apparatus according to claim 2, wherein the cooling fan isdisposed in a position off the circuit board and located side by sidewith the circuit board along a direction parallel to the surfaces of thecircuit board.
 5. An electronic apparatus according to claim 2, whereinthe first heat transfer member and the second heat transfer memberextend along a side face on the same side of the cooling fan.
 6. Anelectronic apparatus according to claim 2, wherein the first surface andthe second surface are an upper surface and a lower surface,respectively, of the circuit board, an end portion of the first heattransfer member attached to the first radiator member is attached to anupper part of the first radiator member, and an end portion of thesecond heat transfer member attached to the second radiator member isattached to a lower part of the second radiator member.
 7. An electronicapparatus according to claim 2, which further comprises a third heatgenerating component mounted on the first surface of the circuit board,a fourth heat generating component mounted on the second surface of thecircuit board, a third radiator member located off the circuit board, afourth radiator member located side by side with the third radiatormember, a third heat transfer member extending along the first surfaceof the circuit board and located between the third heat generatingcomponent and the third radiator member, and a fourth heat transfermember extending along the second surface of the circuit board andlocated between the fourth heat generating component and the fourthradiator member.
 8. An electronic apparatus according to claim 7,wherein an additional exhaust vent opens in a wall of the case, thecooling fan includes an additional exhaust port through which air isdischarged toward the additional exhaust vent, and the third radiatormember and the fourth radiator member are both located between theadditional exhaust port of the cooling fan and the additional exhaustvent of the wall.
 9. An electronic apparatus according to claim 1,wherein the radiator section includes a radiator member, the first heattransfer member is thermally connected to the first heat generatingcomponent and the radiator member, and the second heat transfer memberis thermally connected to the second heat generating component and theradiator member.